1. Field of the Invention
The present invention generally relates to a finger insert to permit improved grip and, more particularly, to finger inserts for use in the holes of a bowling ball.
2. Description of Related Art
The precise fit of a bowling ball to a bowler's fingers has long been a sore spot in this popular sport. It stands to reason that a player's grip on the ball must be sure and secure so that the ball is correctly aimed and propelled down the alley. If the holes into which one inserts one's fingers to grip the ball are too large, the ball may well slip prematurely from one's grasp. The extra effort to hold on to a loose ball may be significant. But if the holes are too small, the player's fingers may become sore and bruised through repeated insertions into the holes. The ball may even hang on to the hand for a moment after release, resulting in further finger damage, as well as gutter balls.
As a result, the usual tradition for serious bowlers has been to obtain a custom-made ball in which the holes are drilled to match the bowler's fingers. Generally, such custom holes are available in 1/32-inch increments, making it possible to closely match the dimensions of a bowler's fingers. However, the human finger is not static. It may swell due to bruising, weight gain, or even to water retention. On the other hand., the finger may shrink due to weight loss. Fingers frequently change diameter during the course of the day; perhaps being smaller in the morning and larger in the evening. In any case, a bowling ball hole that matches the fingers perfectly when it was first drilled may well be too large or too small at a later date. In fact, it is likely that the same hole will alternately be too large and too small.
Some bowlers attempt to solve the changing finger size problem by having more than one bowling ball: say one ball drilled for their fingers at their minimum size and a second ball drilled for the fingers at a maximum size. This solution is not very practical, particularly for a casual player who uses rental balls. Therefore, there has been a considerable inventive effort expended in trying to solve this vexing problem.
A number of special bowling balls that have adjustable finger holes have been disclosed. U.S. Pat. No. 2,372,958 to Keith discloses a finger hole which includes a hollow cylinder of rubber or similar resilient material. The bowler's finger is inserted into the hollow cylinder, and an adjustable compressing device is provided which compresses the hollow cylinder lengthwise, thereby causing the hollow cylinder to decrease in diameter. U.S. Pat. No. 3,012,783 to Bunk shows a bowling ball with a hollow cylindrical insert of flexible material. The insert is compressed to alter its diameter much like '958 to Keith. However, in this device the insert is compressed from its bottom end, whereas the compression in Keith is from the top end.
U.S. Pat. No. 3,004,762 to Frost shows another adjustable insert comprising a hollow cylinder with a longitudinal split in its lateral wall. An adjustment screw presses laterally on the insert, compressing it and reducing the effective size of the finger hole.
U.S. Pat. No. 4,560,162 to Miller discloses an adjustable thumb insert for a bowling ball. A screw is provided which causes a movable shoulder to slide along an inclined plane, forcing the shoulder inward, and thereby narrowing the effective diameter of the insert. Alternatively, a screw rotates an eccentric cam that presses into and decreases the diameter of the thumb insert. U.S. Pat. No. 4,778,178 to Haza show a different way to use an incline plane to adjust an insert. The insert comprises two telescoped tubes with an inclined plane ramp portion between them. Means is provided to rotate the ramp relative to the stationary tubes. The ramp interacts with a portion of the inner tube variably pressing it inward, thereby adjusting the finger hole diameter.
U.S. Pat. No. 2,842,367 to Keith discloses a bowling ball finger insert which is molded of rubber and contains a plurality of hollow compartments within its lateral walls. The insert is designed so that one or more of the compartments can be inflated with air, thereby adjusting the diameter of the finger opening.
U.S. Pat. No. 5,330,392 to Bresin et al. provides an insert of resilient material having concave recesses or flutes in its outer wall. This allows the recesses to collapse under pressure from an inserted finger, thereby automatically adjusting itself to the size of an inserted finger.